(a) Field of the Invention
The present invention relates to a liquid crystal display (LCD).
(b) Description of the Related Art
Generally, an LCD includes a pair of panels each having electrodes on their inner surfaces, and a dielectric anisotropy liquid crystal (LC) layer interposed between the panels. In an LCD, a variation of the voltage difference between the field generating electrodes, i.e., the variation in the strength of an electric field generated by the electrodes, changes the transmittance of the light passing through the LCD, and thus desired images are obtained by controlling the voltage difference between the electrodes.
Depending on the type of light source used for image display, LCDs are divided into three types: transmissive, reflective, and transflective. In transmissive LCDs, pixels are illuminated from behind using a backlight. In reflective LCDs, the pixels are illuminated from the front using incident light originating from the ambient environment. The transflective LCDs combine transmissive and reflective characteristics. Under medium light conditions such as an indoor environment, or under complete darkness conditions, these LCDs are operated in a transmissive mode, while under very bright conditions, such as an outdoor environment, they are operated in a reflective mode.
The transmissive LCD and the transflective LCD are often used since they provide relatively high display luminance compared to the reflective LCD type.
However, in these two types of LCDs, a polarizer attached to a lower surface of the LCD absorbs about 50% of light emitted from the backlight, and therefore only the remaining 50% is used for the display. As a result, light efficiency and display luminance of the LCD are less than optimal.